Improvement in tanning  hides and skins



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C'ESARE OSMA-N 'I, OF TOLENTINO, ITAL'Y.

Letters Patent No. 85,327, dated December 29, 1868; patented in England, January 23, 1868.

MROVEIVIENT IN TANNING- HIDES ANIDSKINS.

The Schedule referred to in these Letten Patent and making part of the same.

To all to whom it may conce'rnr Be'it known that I, OESARE Osnxm, of Tolentino,

declare the nature of the said invention, and in what manner the same is to be performed, to be particularly described and ascertained in by the following statement thereof; that is to say- This invention has for its object improvements in tanning hides and skins. 7

After the hides or skins, as the case may be, have remained the usual period in lime, sons to enable the hair to be completely removed, as well as any particles of flesh still adhering, and the hides are completely purged and cleansed by the action of the lime, the first step in this new process is to fill a vat with sufficient water to cover the quantity of skins which it is intended to place therein. These are to be thrown in, one by one, and well spread out, each with the fleshy side upwards, and sprinkled with bran in the following proportions: I

Light hides for uppers, each skin six ounces.

Calf-skins, each, three ounces. 1

Sheep-skins, each, two and one quarter ounces.

Heavy hides, for sole-leather, each, fourteen ounces.

In this vat the skins must remain until fermentation has taken place, which will be in about two days in warm weather, and a little longer in cold weather, and after this the skins must be removed, and carefully scraped on both sides, so that they may be perfectly freed from any adhering particles of lime or other substances. When this has been done, the skins are subjected to the action of mustard-seed, which forms the distinguishing feature in this new process. It is carried out as follows:

A vat of proportionate size is filled with a suificiency of water to cover the skins which areto be placed therein, and to this water'there must be added for every hundred pounds weight of the skins when dry, five pounds of ground Italian mustard-seed and five poundsof barley-meal. When these ingredients have been thoroughly mixed with the water, the skins must be dipped therein, so that they may beperfectly saturated with it, and they must be left in this dip for the following length of time:

Oalf, sheep, or goat-skins, twenty-ibur hours. Light hides and kips, thirty-six hours. Heavy hides, for sole-leather, forty-eight hours.

When this time has expired the skins must be taken out of the vat and hung up to dry, but only partially,

as when subjected to the next process they shoul still be in a damp condition.

The dip which has just been described has a very powerful action on the skins. The combined action of the mustard seed, barley-meal, and heat thereby generated, is to open the pores of the skins, andthus render the remaining processes in tanning them by means of bark, &tc., much more speedy than under any other methods hitherto known.

I would remark that although I have stated the exact manner in which it is preferred to prepare the skins for the mustard-bath, and also the exact composition of the mustard bath itself, and the time during which it is preferred to subject the several varieties of skins to its action, I do not confine myself thereto, as these may be varied. Other mustard-seed, or oil of mustardseed might also be employed in place of Italian muscard-seed.

So far' the process hitherto described is suited toall descriptions of skins. I

I will now describe the manner in which it ispreferred subsequently to treat each separate kind. This subsequent treatment may-however, be considerably varied, and other tanning-materials may be employed in place of the tanning-materials mentioned.

First-light hides and kips are tanned by undergoing .three baths in water charged with powdered oak-bark.

In each of these three baths the skins must remain eight days. As before mentioned, the skins must be taken, while still damp from the effects of the mustard dip, and placed in a suitable vat with suificicnt water to cover them, charged. with oak-bark in the propor-. tion of two hundred pounds of bark to every hundred. pounds of dry hides. The second and third baths are to be mixed in the same proportions It is necessary tocbserve'that the hides must be moved twice a'day, in orderto change tbepoints of contact between them, and during the second and third baths the barkmust also be taken out, and replaced by degrees, when the skins are put into .the vat again. When mechanical appliances are used by whichfthe .hides are kept in motion while in the tan-water, only two baths, of eight days each, are required, as the bark acts more speedily on the leather. By the method just described, light hides and kips are perfectly tanned in from sixteen to twenty-fdur' days after they have passed into the tanvats, and it only remains to grease and finish them according to the methods employed by tanners in general.

Second, calf-skins are tanned in the foregoing manner also, with this exception, that only two baths, of eight days each, in tan-water, are required. The same quantity of oak-bark must, however, be applied to these two baths as would be required for three in the proportion previously described. Sixteen days are thus required for tanning calf-skins, after which they are to be-finished in the usual manner.

Third, sheep-skins areto be treated in the same manner, but only one bath is requisite in water charged with oak-bark in the proportion of three pounds twelve ounces of bark to each skin. In eight days sheep-skinsare thus completely tanned, and have to be finished as usual.

- Fourth, heavy hides, for sole-leather, owing to their thickness, are the most diflicnlt'of all kinds of skins to tan well. The following directions must be followed out: The hides must be subjected. to three baths, of eight days ch, must then be placed in a tau-pit for eighteen days, and finally, when taken out of this, placed in another tan-pit for forty days. The first bath must be charged with two and one-fifth pounds of oak-bark to a corresponding weight of hides when dry. The second bath must be charged with two pounds of oak bark and twelve ounces of pulverized pine-bark to every two and one-fifth pounds of hides, as before. The third bath must be charged with one pound eight ounces of oak-bark andone pound four ounces of pinebark to every two and one-fifth pounds of hides, as

before. Each of these three baths is to last eight days, during which it is necessary to move the hides frequently, in order to change the points of contact between them, and after this the hides are transferred to a tan-pit and carefully spread out. Tan-water is applied toithem, charged with twelve ounces of fine and good valonia to every two and one-fifth pounds of hides, as before. This mixture is to be rat-her thick, and

must be applied to every stratum of hides superficially. After remaining eighteen days in this tan-pit,

the hides must be taken out, washed in the tan-water, and then spread out in the second tan-pit, between layers of powdered valonia, in the proportion of twelve ounces of valonia to every two and onefifth pounds of hides, as before. Aiter remaining forty days in this secondtan-pit, the hides will be perfectly tanned, and will turn out compact and of a clear color. The time employed is eighty-two days in tanning heavy hides,

after which they have only to be finished accordiu to the methods common to all tanners. If baths 0 stronger tanning-material be employed, the time occuless.

What I claim, isr The subjecting hides and skins to the action of a bath of mustard-seed or oil of mustard, substantially as herein described, to open the pores of the skins, andthus render the process of tanning them by bark or other tanning-material much more speedy than has heretofore been practicable.

f GESARE OSMANI, Witnesses:

p G. F. WARREN, Both of No.17 Gracechurch Tnos. BROWN, Street, London.

pied by the tanning-process would he proportionably 

